Wireline and wireless Internet protocol (IP) networks have traditionally supported a best effort delivery of all traffic. To support enhanced services, multiple types, or classes, of services have been established and assigned certain quality of service (QoS) parameters that manage queues for each service type. The QoS parameters include delay, jitter, error rates, and throughput. The QoS parameters can be provisioned on a per IP connection or per flow basis through mechanisms such as resource reservation protocol (RSVP) or can be provisioned on aggregate flow which are classified into service classes. Internet service providers (ISPs) can utilize the service classes, their associated QoS behavior and QoS provisioning to provide tiered service offerings to their business and consumer customers.
The IP QoS architecture provides tools for marking IP flows, controlling and shaping the traffic of various IP flows, and managing various IP queues in order to ensure QoS behavior for each class of service. Queue management algorithms include head-drop, tail-drop, first in first out (FIFO) and random early detect (RED). The queue management may be on individual microflows or on aggregate flows which are treated with similar QoS behavior.
Techniques such as Multiprotocol Label Switching (MPLS) are being developed to combine layer 2 switching and layer 3 routing. MPLS is a unified approach to create a flexible network fabric for increased performance, scalability, and for traffic engineering to enable virtual private networks (VPN) and QoS.
Proposals for IP QoS on wireless networks have focused on combating the error-prone wireless links. For example, ensuring efficient transport control protocol (TCP) performance over an error-prone link as well as renegotiating QoS parameters and reallocating resources as error rates and/or error link performance values degrade. Both MPLS and IP QoS architecture for wireless networks, however, are not sensitive to the mobility, nomadicity (anytime, anywhere), interference, and radio bandwith characteristics of the air interface. This limits effective application throughput, consistency across the network, overall network efficiency, and rapid service creation.